Magnetic resonance imaging (“MR”) is a well known, highly useful technique for diagnosing abnormalities in biological tissue. MRI can detect abnormalities that are difficult or impossible to detect by other techniques, without the use of x-rays or invasive procedures.
MRI can be of great assistance during medical procedures. For example, MRI has been used for pre-operative and postoperative imaging to identify and assess the condition of tissue of interest. MRI has also been used during fine-needle aspiration cytology to help the doctor guide the needle to the site of interest, such as a tumor. See, for example, U.S. Pat. No. 6,208,145 B1, assigned to the assignee of the present invention and incorporated by reference, herein. MRI has also been used in stereotactic neurosurgery. The advance of other instruments, such as a catheter or an endoscope, can also be followed and guided to a site of interest by MRI. See, for example, U.S. Pat. No. 6,249,695 B1 and U.S. Pat. No. 5,647,361, which are both assigned to the assignee of the present invention and incorporated by reference, herein. The catheter can be used in the treatment of the tissue of interest, such as a tumor, by delivering medication, isotopes or other such treatments, for example. The effect of the treatment on the tissue may also be monitored by MRI, as the treatment is being conducted. See for example, U.S. Pat. No. 6,208,145 B1 and U.S. Pat. No. 6,280,383 B1, both assigned to the assignee of the present invention and incorporated by reference herein.
MRI systems are available with imaging volumes large enough to conduct surgery and other medical procedures. For example, in U.S. Pat. No. 6,208,145 B1, assigned to the assignee of the present invention and incorporated by reference herein, an open MRI assembly is disclosed wherein a physician or other medical personnel may conduct activities within the frame of the assembly, adjacent to the patient.
The magnet assembly of the MRI system may define a room for conducting a medical procedure and may be large enough to contain an entire surgical team. See, for example, U.S. Pat. No. 6,201,394 B1, assigned to the assignee of the present invention and incorporated by reference herein. The Quad™ 7000 and Quad™ 12000 Open MRI Systems, available from FONAR Corporation, Melville, N.Y., are also suitable for performing surgery and other medical procedures.
Rooms for conducting medical procedures, particularly rooms for conducting surgery, typically use large overhead lights for illumination. The lights are often fluorescent. The position and/or direction of the lights are usually adjustable so that the surgeon or other personnel can direct the light onto the site of interest. Typical medical lighting cannot be placed into the imaging volume of an MRI system, however, because fluorescent lighting may interfere with the magnetic field generated by the MRI System. In addition, in an Open MRI System, the upper pole can cast a shadow within the imaging volume.
An improved lighting system is needed to facilitate the performance of medical procedures in an imaging volume of an MRI system.